Method of Delivering, Storing, Unloading, and Using Proppant at a Well Site

ABSTRACT

A proppant discharge system has a container with an outlet formed at a bottom thereof and a gate slidably affixed at the outlet so as to be movable between a first position covering the outlet to second position opening the outlet, and a support structure having an actuator thereon. The container is removably positioned on the top surface of the support structure. The actuator is engageable with gate so as to move the gate from the first position to the second position. A conveyor underlies the container so as to receive proppant as discharged from the container through the outlet. The container is a ten foot ISO container.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/628,702, filed Sep. 27, 2012, which is a continuation-in-part of U.S.patent application Ser. No. 13/555,635, filed Jul. 23, 2012, all ofwhich are incorporated herein by reference in their entireties.

BACKGROUND

1. Field of the Invention

The present invention relates to storage containers. More particularly,the present invention relates to proppant discharge systems whereinproppant can be discharged from the storage container. Additionally, thepresent invention relates to a process for providing proppant to a wellsite by the transport and delivery of the proppant containers.

2. Description of Related Art

Hydraulic fracturing is the propagation of fractions in a rock layercaused by the presence of pressurized fluid. Hydraulic fractures mayform naturally, in the case of veins or dikes, or may be man-made inorder to release petroleum, natural gas, coal seam gas, or othersubstances for extraction. Fracturing is done from a wellbore drilledinto reservoir rock formations. The energy from the injection of ahighly-pressurized fracking fluid creates new channels in the rock whichcan increase the extraction rates and ultimate recovery of fossil fuels.The fracture width is typically maintained after the injection byintroducing a proppant into the injected fluid. Proppant is a material,such as grains of sand, ceramic, or other particulates, that prevent thefractures from closing when the injection is stopped.

With the rise of hydraulic fracturing over the past decade, there is asteep climb in proppant demand. Global supplies are currently tight. Thenumber of proppant suppliers worldwide has increased since 2000 from ahandful to well over fifty sand, ceramic proppant and resin-coatproducers.

By the far the dominant proppant is silica sand, made up of ancientweathered quartz, the most common mineral in the Earth's continentalcrust. Unlike common sand, which often feels gritty when rubbed betweenthe fingers, sand used as a proppant tends to roll to the touch as aresult of its round, spherical shape and tightly-graded particledistribution. Sand quality is a function of both deposit and processing.Grain size is critical, as any given proppant must reliably fall withincertain mesh ranges, subject to downhole conditions and completiondesign. Generally, coarser proppant allows the higher now capacity dueto the larger pore spaces between grains. However, it may break down orcrush more readily under stress due to the relatively fewergrain-to-grain contact points to bear the stress often incurred in deepoil- and gas-bearing formations.

Typically, in any hydraulic fracturing operation, a large amount of suchproppant is required. Typically, it has been difficult to effectivelystore the proppant at the fracturing sites. Additionally, it has beenfound to be rather difficult to effectively transport the proppant tothe desired location. Often, proppant is hauled to the desired locationson the back of trucks and is clumped onsite. Under such circumstances,the proppant is often exposed to adverse weather conditions. This willeffectively degrade the quality of the proppant during its storage.Additionally, the maintenance of proppant in containers at the hydraulicfracturing site requires a large capital investment in storagefacilities. Typically, the unloading of such storage facilities iscarried out on a facility-by-facility basis. As such, there is a need tobe able to effectively transport the proppant to and store the proppantin a desired location adjacent to the hydraulic fracturing location.

With the development and acceptance of the well stimulation methodologyknown as “hydraulic fracturing”, a unique logistics challenge has beencreated in delivering the massive quantities of proppant from domesticsand mines to the wellhead. This logistics challenge affects everystakeholder up-and-down the logistics chain. In particular, thisincludes sand mine owners, railroads, trans-loading facilities,oil-field service companies, trucking companies and exploration andproduction companies. The existing method of delivering sand to theconsumer requires the use of expensive specialized equipment and a highlevel of coordination. This makes the process subject to a myriad ofproblems that disrupt the efficient flow of proppant to the wellhead.The result of utilizing the current method is the expenditure ofhundreds of millions of dollars in largely unnecessary logistics costs.

Sand mines are being rapidly developed all over the United States tosatisfy the demand that the “Shale Boom” has created for proppant. Mostof the recent mines that have come on-line, or are in varying stages ofdevelopment, have limited transportation infrastructure to support theexport of sand from the sand-pit. As a result, many mines are buildingrail-spurs that will accommodate up to 100 rail cars or more that can beloaded and stand for transportation to the designated destination. Alongwith rail-track, these companies are also investing in expensivevertical silo storage facilities to store thousands of tons of proppant.The sand mines are unable to effectively ship proppant to the shaleregions without equal fluid trans-loading and storage facilities on thereceiving end of the logistics chain. This results in lost revenue andproductivity for the mine owner and higher prices for proppant buyers inthe destination region.

Railroads are a critical part of the logistics chain required to moveproppant from mine to the various shale regions. Due to the lack of railtrack and trans-loading facilities in some of these remote regions, therailroad companies must be selective of their customers' deliverylocations, and make sure that their customers have the ability toefficiently off-load rail cars. Recently, the railroads have seen theallocated fleet of hopper cars being stranded at those destinationswhere there is no cost-effective storage option to efficiently off-loadthose cars. Consequently, there has been a significant opportunity costthat the railroads have been forced to pay. As such, a need hasdeveloped for facilitating the ability to quickly and inexpensivelyoff-load proppant from rail cars so as to enable the railroads toimprove the velocity, turn-around and revenue-generating capacity of therail-car fleet.

Limited storage at trans-loading facilities has severely limited many ofthe current facilities' ability to operate efficiently. Most trans-loadfacilities are forced to off-load rail hopper cars by bringing in trucks(i.e. pneumatics) along the rail siding, and conveying sand directlyfrom rail to truck. This requires an intense coordination effort on thepart of the trans-loader as well as the trucking community. Long trucklines are commonplace, and demurrage fees (i.e. waiting time charged bytrucking companies) amount to hundreds of millions of dollarsnationwide. As such, the trans-loader is not able to fully realize theutilization of conveying and other material handling equipment. Thethroughput of these trans-loading terminals severely reduces costing ofthe terminal meaningful revenue.

Additionally, optimal trans-load terminal locations are immobile and notable to move from one area of the shale pay to another. Investors inimmobile silo and flat storage facilities can see the utilization andvalue of those investments tumble. A potential loss of the investment insuch immobile silos can often scare investment capital away from thesetypes of future projects so as to further exacerbate the logistics chainproblem. As such, a need has developed for a portable, inexpensivestorage and delivery solution for proppant that would help revive thecapital needed to improve the facilities and maximize therevenue-generating potential of existing and new trans-load and storagefacilities.

The lack of efficient trans-load and storage facilities in shale regionshave taken a heavy toll on the efficiencies of trucking fleets. Whiletrucking companies have typically charged demurrage fees to compensatefor the waiting time and lost productivity, those types of charges areunder significant resistance from the customer base. When truckingcompanies are required to wait in line to be loaded, or wait at awell-site to be unloaded, the number of turns that the equipment canmake in a day is severely limited. Rather than turning two or threeloads in a single day, the trucks more typically make one trip per day,and very commonly may make one delivery every two or three days, Thislack of efficient fleet utilization results in the trucking, companyhaving to buy more equipment and hire more drivers to move the sameamount of material than would be necessary. As such, it would bedesirable to eliminate demurrage charges and to present the opportunityfor trucking companies to become more profitable while making smallerinvestments in equipment.

Service companies (such as fracturing companies) are held captive by thecurrent proppant delivery process. This is the result of inefficienttrans-load facilities and pneumatic (bulk) truck deliveries. The servicecompany cannot frac a well if it does not have a supply of proppant. Itis widely known that the problems surrounding the efficient delivery ofproppant to the well-site is one of the primary challenges to theservice companies in successfully completing a frac job. Pressure pumps,coiled tubing and other well stimulation equipment, often site idle dueto the lack of required proppant at the well-site, “Screening-Out” orrunning out of proppant is very common at well locations due to the lackof control over what is happening up-stream in the proppant logisticschain. This results in lower profit margins to the service company. Manysmall to medium-sized hydraulic fracturing companies have little or nologistics infrastructure. Some have entered the marketplace without muchthought to the logistics problems associated with taking delivery of thenecessary supplies to complete a well. In doing so, many of thesecompanies have been forced to source material and employ very expensivelogistics options in order to survive. This has resulted in above-marketpricing in order to complete wells. There is also as risk of losing outon otherwise viable hydraulic fracturing contracts. As such, there is aneed to lower costs across the board in order to properly compete.

Exploration and production companies, along with the entire U.S.population, pay the ultimate bill for all of the inefficiencies andwaste that plagues the proppant supply chain Service companies areforced to price hydraulic fracturing services by taking into account thehistorical costs of supply chain problems. Exploration and productioncompanies need to pass on the overall increased cost of production. Assuch, there is a need to provide a cost-effective solution to improvethe profitability of stake holders in the proppant logistics chain,while lowering the overall cost to the consumer.

U.S. patent application Ser. No. 13/427,140, filed on Mar. 22, 2012 bythe present inventor, describes a system for the delivery of proppantbetween a loading station and the well site. This application describesthe steps of placing the storage container in a location adjacent to atrain site such that the proppant, as delivered by the train, can bedischarged into the container. The container can then be transported forstorage in stacks at the loading area or can be delivered to a tiltingmechanism at the loading station. The tilting station will tilt thecontainer so as to allow the proppant to flow outwardly therefrom. Thisproppant will flow, by a conveyor, to a pneumatic truck. The truck canthen transport the proppant over the highways to the well site. At thewell site, the proppant from the pneumatic truck can then be dischargedinto a twenty foot container at the well site. These twenty footcontainers can be stored at the well site in a stacked configuration.Ultimately, each of the containers can be transported to another tiltingmechanism at the well site so that the proppant within each of thestorage containers can be discharged onto a conveyor and ultimately foruse during the fracturing operation.

In this U.S. patent application Ser. No. 13/427,140, the twenty-foot ISOcontainer that is utilized is one of the most inexpensive andreadily-available pieces of transportation equipment in the world. Itwas determined that the use of the twenty-foot container allows for thetransportation of proppant through various minor modifications to theinternal walls and reinforcements of the twenty-foot ISO container. Theavailable capacity is more than acceptable. It was determined that thismodified twenty-foot container could hold in excess of forty-five tonsof proppant. The cost of an unmodified twenty-foot ISO container is lessthan four thousand dollars. This makes it very affordable compared tothe cost of building, vertical silos or flat storage buildings.

The twenty-foot ISO container was modified by cutting a hole in the topof the container and constructing a water-tight, hinged hatch throughwhich the proppant could be poured by any number of readily-availableconveying units. There was also a lower hatch in the twenty-foot ISOcontainer. This lower hatch could be opened to drain the proppant out ofthe twenty-foot ISO container. Alternatively, a square flow-gate wasfabricated and welded to the vertical rear lower side of the twenty-footcontainer. This gate hatch allowed the container to be tilted in themanner of a dump truck bed. As a result, sand could flow out of the flowgate while moderating the flow of the sand.

This patent application provided the ability to trans-load sand viacontainers from a standard rail hopper car to the twenty-foot ISOcontainer. It was determined that the container could be loaded in lessthan twenty minutes with at least fort-five tons of proppant. Bypre-positioning the container along, the rail track, movable conveyorscould work the train from one end to the other and unload the train in avery efficient and timely manner. This part of the process eliminatedthe coordination efforts of calling in pneumatic trucks that could besystematically loaded by conveying units. This reduced the timenecessary to unload a train's hopper cars by many hours. It alsoeliminated truck traffic and demurrage charges at the rail-spur andtrans-load facility.

Once the proppant is loaded into the container, another piece ofspecialized equipment would be used to lift the full container and tostack the container upon other containers. The stackable arrangement ofcontainers allows the ability to operate and store proppant within avery small footprint. The specialized equipment that was required tolift the full containers was so heavy and large that it would have to bedisassembled into several pieces before moving from one location toanother. This created some limitations on the flexibility that suchequipment lent to the containerized process.

By “containerizing” proppant, it was found that an inventory managementsystem could be added in order to provide real-time, accurateinformation pertaining to the volume/inventory of proppant that thecustomers own in a particular region. Currently, many proppant buyersare subject to inaccurate volume reporting from trans-loadingfacilities. As such, they May not be certain that the proppant beingdelivered to the well-site is, in fact, of the quality and grade thatthey have purchased. By applying an inventory management system, barcoding, and scanning the containers into and out of inventory, thecustomers would be assured that they have received, their proppant andwould be able streamline the procurement process when ordering morematerial.

In this prior process, since the twenty-foot ISO container needed to beemptied and trans-loaded into pneumatic trailers for delivery to thewellhead, a tilting unit was incorporated into the process. This tiltingunit accepted the twenty-foot ISO containers. The tilting unit is ableto lift one end of the container and create the required angle to whollyempty the container through the flow gate. Once tilted, the sand wouldspill onto the belt of the conveyor and rise vertically into a hopper.The hopper rested on a steel fabrication stand. This stand is highenough such that a truck that pulls a pneumatic trailer could driveunder the stand and be gravity fed by the hopper so as to fill up thesand trailer. These “loading stations” could be replicated along a pathso as to alleviate the bottleneck of trucks at a trans-load facilitythat has a limited number of conveyors available to load the trucks.Once again, trucking demurrage at this trans-load facility could bedramatically reduced through the process. The railcars can be off-loadedrapidly and released back to the railroads. This also reduced oreliminated demurrage fees charged by the railroads for rail hopper carsthat stood waiting to be off-loaded.

This prior process created an inexpensive storage solution, improved theefficiencies of the trans-loading process, added inventory visibilityand controls, and reduced both truck and rail demurrage charges.However, it did have several limitations. For example, the twenty-footISO container, while capable of handling ninety thousand pounds ofproppant, could not be transported legally over a public road. In moststates, the maximum allowable total weight of a vehicle and its payloadis eighty thousand pounds of gross vehicle weight in order to beconsidered a legal load. By law, any load that can be broken down by twounits or more, in order to achieve a legal weight limit, must be dividedinto multiple loads. Since proppant is divisible, the law does not allowfor heavy or over-weight loads.

The angle of repose of a granular material is the steepest angle ofdescent or dip of the slope relative to the horizontal plane whenmaterial on the slope face is on the verge of sliding. When bulkgranular materials are poured onto a horizontal surface, a conical pilewill form. The internal angle between the surface of the pile and thehorizontal surface is known as the angle of repose and is related to thedensity, surface area and shape of the particles, and the coefficient offriction of the material. The angle of repose is also gravity-dependent.

When analyzing the angle of repose of proppant poured into a twenty-footISO container, it was evident that much of the volume of such acontainer was void. Specifically, the upper ends of twenty-foot ISOcontainer could not be utilized without somehow manipulating or tiltingthe container as it was filled by a conveyor. Moreover, when emptyingthe container, by way of the original bottom hatch, the proppant wouldpour directly out of the bottom and leave a significant amount ofmaterial sitting on the floor of the container.

U.S. patent application Ser. No. 13/555,635, filed on Jul. 23, 2012 bythe present inventor, is the parent of the present application. U.S.patent application Ser. No. 13/555,635 described a new generation of thecontainer by taking the original twenty-foot ISO container and splittingit in half. As such, a ten foot ISO container was provided. By breakingthe container into a ten foot configuration, it was determined that sucha container could hold approximately 45,000-48,000 pounds of proppant.The total gross vehicle weight of such a fully-loaded container could belegally transported over a public road. This was a major breakthrough.The container could be delivered to the wellhead in advance of a fraccrew and eliminate sand deliveries during the fracturing process.Because all of the required proppant for any frac job could be deliveredand stored on-site, such a ten-foot ISO container effectively eliminatedthe occurrence of trucking demurrage charges at the well-site. Also, theuse of such a ten-foot container effectively eliminated the problemscaused by the angle of repose of the proppant and allowed the volumetriccapacity of such a ten-foot ISO container to be more fully utilized. Itwas found to be the optimal configuration, size, and cost for theprocess.

This prior application utilized an insert that is fabricated, and weldedwithin the interior of the ten-foot ISO container. The insert allowed,the proppant, loaded through the top hatch, to fully flow out of a newlydesigned bottom flow-gate. The need to manipulate or tilt the containerwas eliminated. This ten-foot container could now be filled and emptiedby using only gravity to do so.

In the past, various patents have issued relating to storage andtransport facilities. For example, U.S. Patent Publication No.2008/0179054, published on Jul. 31, 2008 to McGough et al., shows a bulkmaterial storage and transportation system. In particular, the storagesystem is mounted on the trailer of a truck. The storage system includeswalls that define an interior volume suitable for receiving theaggregate material therein. There are hoppers provided at the bottom ofthe container. These hoppers have inclined walls. The hoppers can extendso as to allow the material from the inside of the container to beproperly conveyed to a location exterior of the container. Actuators areused so as to expand and collapse the container.

U.S. Pat. No. 7,240,681, issued on Jul. 10, 2007 to L. Saik, describes atrailer-mounted mobile apparatus for dewatering and recovering formationsand. The trailer is mounted to a truck-towable trailer so as to receivesand therein. The container has a pair of sloping end walls. The backend of the container is suitably openable so as to allow the sand to beremoved therefrom. A pneumatic or hydraulic ram is provided on theforward part of the container so as to allow the container to be liftedangularly upwardly so as to allow sand to be discharged through the gateat the rear of the container.

U.S. Pat. No. 4,247,228, issued on Jan. 27, 1981 to Gray et al.,describes a dump truck or trailer with a pneumatic conveyor. Thecontainer is mounted to a frame on wheels. A hydraulic ram tilts thecontainer for dumping through a rear outlet. A pneumatic conveyor iscarried by the frame with an intake at the rear of the container. A gateallows the solids to be dumped conventionally by gravity or to be blownto a storage facility by the pneumatic container. The container has atop hatch formed therein so as to allow the solids to be introduced intothe interior of the container.

U.S. Pat. No. 2,865,521, issued on Dec. 23, 1958 to Fisher et al., showsa bulk material truck that has an interior volume suitable for thereceipt of bulk material therein. A pneumatic conveyer is utilized so asto allow the removal of such material from the bottom of the container.A pair of sloping walls are provided on opposite sides of the containerso as to allow the bulk material within the container to be passedtoward the bottom of the container. A top hatch is provided on the topof the conveyer. The pneumatic conveyer is connected to the bottom ofthe container.

It is an object of the present invention to provide a proppant storagecontainer that allows proppant to be easily transported and stored.

It is another object of the present invention to provide a proppantstorage container that allows the proppant to be easily and efficientlydischarged to the bottom of the container.

It is another object of the present invention to provide a proppantstorage container which allows for the effective storage of proppant atthe fracturing site.

It is another object of the present invention to provide a process fordelivering proppants that eliminates the use of pneumatic trailers.

It is further object of the present invention to provide a proppantstorage container and a process for delivering proppant in which of thecontainers can be moved by a simple forklift.

It is another object of the present invention to provide a process fordelivering proppants which effectively eliminates demurrage associatedwith the loading station and at the well site.

It is a further object of the present invention to provide a process ofthe deliver proppant which avoids the degradation of the proppant as aresult of repeated handling.

It is a further object of the present invention to provide a proppantdischarge system which provides a premeasured amount of proppant to thedrill site.

it is still another object of the present invention to provide aproppant container which satisfies highway regulation and which has lessvoid space within the interior of the container.

These and other objects and advantages of the present invention willbecome apparent from a reading of the attached specification andappended claims.

SUMMARY

The present invention is a container for the transport and storage ofproppant. The container comprises a box having a bottom, a pair of sidewalls a pair of end walls and a top. The box has an inlet formed at oradjacent to the top. The box has an outlet at the bottom. A gate ispositioned at the outlet. The gate is slidably movable between a firstposition covering the outlet and a second position opening the outlet.

A first ramp extends from one of the pair of sidewalls to the outlet. Asecond ramp extends from the other of the pair of sidewalls to theoutlet. A third ramp extends from one pair of end walls to the outlet. Afourth ramp extends from the other of the pair of end walls to theoutlet. The box has a track formed on the bottom thereof. The gate ispositioned in the track. The gate has a pin extending outwardlytherefrom. The box has a frame formed on an exterior thereof. The frameextends across the pair of sidewalls and the pair of end walls. Theramps have exterior surfaces exposed through the frame. The box has acapacity of up to 48,000 pounds of the proppant. The box is a ten-footISO container.

present invention is also a proppant discharge system that has acontainer with a pair of sidewalls, a pair of end walls, a bottom and atop. The container has an inlet formed at or adjacent to the top. Thecontainer has an outlet formed at the bottom thereof A gate is slidablyaffixed at the outlet of the container so to be movable between a firstposition covering the outlet and a second position opening the outlet. Asupport structure has a top surface and at least one actuator. Thecontainer is removably positioned on the top surface of the supportstructure. The actuator is engageable with the gate so as to move thegate from the first position to the second position.

In particular, the gate has a pin extending therefrom. The actuator hasa receptacle. The pin is receivable within the receptacle.

A conveyor underlies the top surface of the support structure so as toreceive proppant as discharged from the container through the outlet ofthe container. A hopper is positioned on the support structure below thetop surface thereof. The hopper is positioned directly below the gate ofthe container. The hopper has an opening at a bottom thereof. The bottomof the hopper is positioned above the conveyor. A metering gate ispositioned adjacent to the opening at the bottom of the hopper meteringgate. The metering gate is movable between a closed position and an openposition. The opening at the bottom of the hopper has a plurality ofslots formed therein. The metering gate also has a plurality of slotsformed therethrough. The plurality of slots of the metering gate are atleast partially aligned with the plurality of slots of the hopper whenthe metering gate is in the open position. The opening, at the bottom ofthe hopper has an inverted V-shape configuration. The metering rate hasan inverted V-shaped configuration matching with the opening at thebottom of the hopper. The metering gate is slidable relative to theopening at the bottom of the hopper. An actuator affixed to the meteringgate so as to move the metering gate between the closed position and theopen position.

A frame is affixed to the conveyor and extends therealong. A dischargechute is connected to the frame and is cooperative with the end of theconveyor so as to discharge the proppant from the conveyor to a desiredlocation. A plurality of wheels can be rotatably mounted to the frame soas to allow the conveyor to be transported to the desired location.

The present invention is also as process for delivering proppant to afracturing site. This process includes the steps of (1) fanning acontainer having, an interior suitable for receiving the proppanttherein and having an outlet at a bottom thereof; (2) filling thecontainer with the proppant; (3) moving the filled container along, aroadway to the fracturing site; (4) placing the filled container upon aconveyor structure; (5) discharging the proppant from the outlet of thecontainer onto the conveyor, and (6) conveying the discharged proppantto a desired location at the fracturing site.

In this process of present invention, the step of forming includesforming the container so as to have a length of approximately ten feet.A gate is placed over the outlet of the container. The gate is movablebetween a first position closing the outlet and a second positionopening the outlet. The conveyor structure has an actuator thereon. Thisactuator is connected to a receptacle. The gate has a pin extendingoutwardly therefrom. The pin is positioned into the receptacle of theactuator and the actuator is actuated so as to move the gate from thefirst position to the second position. The conveyor structure has ahopper is positioned below a top surface thereof. The hopper has ametering gate at a bottom thereof. The metering gate is positioned abovethe conveyor of the conveyor structure. The filled container ispositioned directly above the hopper of the conveyor structure. Theproppant is discharged from the outlet of the container into the hopperof the conveyor structure. The proppant is metered through the meteringgate at a control flow rate so as to be discharged therefrom onto theconveyor.

The process of the present invention further includes the steps ofplacing the filled container upon a train, transporting the filledcontainer on the train to a location, removing the filled container fromthe train, and placing the removed filled container onto a vehicle.

This foregoing section is intended to describe, with particularity, thepreferred embodiments of the present invention. It is understood thatmodifications to these preferred embodiments can be made within thescope of the present invention. As such, this section should not beconstrued, in any way; as limiting of the true scope of the presentinvention. The present invention should only be limited by the followingclaims and their legal equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the container in accordance with thepreferred embodiment of the present invention.

FIG. 2 is a side elevational view of the container in accordance withthe preferred embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the container of the preferredembodiment of the present invention.

FIG. 4 is a plan view showing the interior of the container of thepreferred embodiment of the present invention.

FIG. 5 is an isolated end view showing the support structure of thesystem of the preferred embodiment of the present invention.

FIG. 6 is a plan view of the support structure of the system of thepresent invention.

FIG. 7 is an end view showing the placement of the container upon thesupport structure in accordance with the preferred embodiment of thesystem of the present invention.

FIG. 8 is a side view of the container as place on the support structurein accordance with the preferred embodiment of the system of the presentinvention.

FIG. 9 is a side devotional view showing a plurality of containers asplaced upon the support structure in accordance with the system of thepreferred embodiment of the present invention.

FIG. 10 is a plan view showing a plurality of containers as placed uponthe support structure in accordance with the preferred embodiment of thesystem of the present invention.

DETAILED DESCRIPTION

Referring to FIG. 1, there is shown the container 10 in accordance withthe preferred embodiment of the present invention. The container 10 isin the nature of a box 12 having an exterior frame 14. The box 12includes a top 16, a bottom 18, an end wall 20 and a side wall 22. Theside wall 24 is opposite to the side wall 22. There also an end wall 26that is opposite to that of end will 20. An inlet 28 is formed throughthe top 16 of the box 12. A hatch 30 is removably or hingedly affixedover the inlet 28 so as to allow proppant to be introduced into theinterior volume of the container 10.

In FIG. 1, it can be seen that the frame 14 extends generally around theexterior of the end walls 20 and 26 and over the side walls 22 and 24.As such as will be described hereinafter, there is a funnel-shapedbottom of the container that has exterior surfaces exposed through theframe 14. During the course of international shipment, it isadvantageous to avoid closed spaces within such a container. As such,the exposure of the surfaces through the openings 32 at the bottom ofthe frame 14 will allow inspectors to have visual access to the areasadjacent to this funnel-shaped area.

As can be seen in FIG. 2, the container 10 is illustrated, as having thetop 16 and the bottom 18. The frame 14 provides structural support forthe container 10 and generally surrounds the exterior of the container.The frame is formed of a plurality of vertical bars that extend so as toform a cage-like configuration around the walls 20, 22, 24 and 26. Thebottom 18 is generally of a planar shape so that the bottom 18 can beplaced upon the support structure (to be described hereinafter). Thearea 32 shows that the funnel-shaped portion 34 is exposed through theopenings of the frame 14. As such, there will be no closed or sealedareas within the interior of the container 10. The hatch 30 ispositioned over the inlet 28 at the top 16 of the container 10. As aresult, the proppant can be introduced through the inlet 28 when thehatch 30 is opened so as to fill the interior volume of the container10. The funnel-shaped, area 34 defines an outlet 36 located at thebottom 18 of the container 10.

As can be seen in FIGS. 1 and 2, the container 10 is a ten-foot ISOcontainer. In accordance with standard ISO terminology, this means thatthe container has a length of ten feet, a width of eight feet and aheight of 8.5 feet. The height can also be 9.5 feet. This configurationallows between 43,000 and 48,000 pounds of proppant to be introducedinto the interior volume or the container.

FIG. 3 shows a partial cross-sectional view of the container 10. It canbe seen that the container 10 has an interior volume 38. The outlet 36is formed adjacent to the bottom 18 of the container 10. A first ramp 40will extend from the end wall 20 to the outlet 36. A second ramp 42 willextend from the end wall 22 to the outlet 36. The ramps 40 and 42 willserve to funnel, the proppant that is retained within the interiorvolume 38 of the container 10 toward the outlet 36. A gate 44 ispositioned within a track 46 located at the bottom 18 of the container10. The gate 44 is in the nature of flat plate which, as shown in FIG.3, covers the outlet 36. The gate 44 includes a pin 48 (in the nature ofking bolt) that extends outwardly from the gate 44. When an actuator isconnected to the pin 48, it can move the gate 44 from the positionclosing the outlet 36 to a position opening the outlet 36. Allow 50shows the movement of the gate 44 between these positions. Since thegate 44 has a width that generally corresponds to the size of the outlet36, the gate 44 will only need to move for a small amount of travel soas to move the gate 44 to the open position.

FIG. 4 is an interior view of the container 10. As can be seen, thefirst ramp 40 will extend from the end wall 20 to the outlet 36. Thesecond ramp 42 extends from the end wall 26 to the outlet 36. A thirdramp 52 will extend from the side wall 22 to the outlet 36. Another ramp54 will extend horn the side wall 24 to the outlet 36. As such, theramps 40, 42, 52 and 54 form the funnel-like shape so that the proppantthat is received within the interior volume 38 of the container 10 canflow free downwardly toward the outlet 36.

In FIG. 4, it can be seen that the gate 44 is positioned within thetrack 46. FIG. 4 shows the gate 44 in its closed position. An actuatorcan be used so as to move the gate 44 from the position shown in FIG. 4in a direct on toward either the side wall 22 or the side wall 24. Pins48 and 58 are illustrated as extending outwardly of the sides of thegate 44. As such, a suitable actuator, such as a hydraulicpiston-and-cylinder arrangement, can be connected to these pins 48and/or 50 so as to achieve the requisite movement of the gate 44 fromthe closed position to the open position.

FIG. 5 is an end view showing the support structure 60 as used in theproppant discharge system of the present invention. The supportstructure 60 has a frame 62 which forms a top surface 64, a bottomsurface 66, and sides 68 and 70. The top 64 of the frame 62 has asurface upon which the container 10 can be placed. Suitable pinconnections 72 and 74 extend upwardly from the top surface 64 so as toengage corresponding receptacles on the container 10. These pins 72 and74 can be utilized so as to assure that the container 10 is properlypositioned upon the support structure 60.

A receptacle 76 is positioned at or adjacent to the top surface 64. Theactuator 78 is affixed to the frame 62 and extends to the receptacle 76.As can be seen, the receptacle 76 has a slot formed in the top endthereof. The slot of the receptacle 76 is suitable for receiving one ofthe pins 48 and 58 of the gate 44 of the container 10. Once thereceptacle 76 receives the pin 48 therein, the actuator 78 can beactuated so as to move the receptacle (and its received pin) from thefirst position 80 to a second position 82. When the receptacle 82 (alongwith the pin received therein) is moved to the second position 82, thegate 44 will be opened so that the proppant can be discharged throughthe outlet 36 of the container 10. Since pins 48 and 58 aresymmetrically placed, and since the container 10 is rather symmetrical,the support, structure 60 is particularly adapted to the variety oforientations with the container 10 can be placed upon the top surface64.

In FIG. 5, it can be seen that there is a hopper 84 that is positionedbelow the top surface 64. Hopper 84 serves to receive a portion of theproppant as discharged through the outlet 36 of the container 10 whenthe gate 44 is in the open position. As such, the hopper 84 can beutilized so as to properly meter the proppant onto the conveyor 86.Conveyor 86 is located below the opening 88 of the hopper 84.

As can be seen in FIG. 5, hopper 84 has an opening 88 of a generallyinverted V-shaped configuration. There is a metering gate 90 that ismated with the opening 88 and also has a V-shaped configuration. Themetering gate 90 can be moved a small distance so as to allow for theselected and controlled discharge of proppant from the hopper 84 ontothe conveyor 86.

FIG. 6 shows the interior of the hopper 84. Hopper 84 includes sidewalls 92 and 94 and end walls 96 and 98. The walls 92, 94, 96 and 98 areformed into a funnel-like shape so as to move the proppant downwardlytoward the metering gate 90. In FIG. 6, it can be seen that the opening88 of the hopper 84 has a plurality of slots formed therein. Similarly,the metering gate 90 has a plurality of slots formed therethrough. Thestructures between the slots are solid. As such, when the slots of themetering gate 90 are aligned with the slots of the opening 88, thenproppant can be discharged onto the underlying conveyor 86. A smallmovement of the metering gate 90 in one direction or another, will blockthe flow of the proppant through the slots of the opening 88 of hopper84. As such, very small actuators 100 and 102 can be used so as toachieve the proper metering of the proppant onto the conveyor. If asmall flow rate of proppant is desired, then the actuators 100 and 102will move the metering gate 90 only a small distance. If a greater flowrate is required, then the actuators 100 and 102 will move the meteringgate 90 so that the slots of the metering, gate 90 fully correspond withthe slots of the opening 88 so as to achieve a maximum flow of proppantfrom the hopper 84 down to the conveyor.

FIG. 7 shows the container 10 as placed upon the top surface 64 of thesupport structure 60. In normal use, a forklift can be utilized so as toproperly position the container 10 in a proper position upon the pins 72and 74 of the support structure 60. Initially, the gate 44 of thecontainer 10 will be closed. Additionally, the metering gate 90 can alsobe closed. When the container 10 is properly positioned, the gate 44 canbe moved to an open position so that the proppant is discharged into thehopper 84. The hopper 84 can then be filled with proppant. When it isdesired to move the proppant from the hopper 84, along the conveyor, tothe desired destination, then the metering gate 90 can be opened so asto achieve the desired flow rate of proppant through the opening 88 ofthe hopper 84.

FIG. 8 shows a side view in which the container 10 is placed upon thetop surface 64 of the support structure 60. The conveyor 86 isillustrated as extending longitudinally. As such when the proppantpasses through the metering gate 90 associated with the hopper 84, anyproppant within the interior volume 38 of the container 10 can bedelivered, in a controlled manner, onto the conveyor.

FIG. 9 is an illustration of containers 110, 112, 114 and 116 as placedupon the support structure 118. The support structure 118 has asufficient length so as to accommodate the containers 110, 112, 114 and116. It can be seen that the conveyor 120 is arranged beneath the topsurface of the support structure 118 and below the respective hoppers122, 124, 126 and 128 below the respective containers 110, 112, 114 and116. The conveyor 120 is an endless conveyor that is suitably woundaround sheaves and idlers so as to travel a desired path. The proppantthat is discharged from the containers 110, 112, 114 and 116 isdischarged onto the conveyor 120 so as to travel therealong and alongupwardly extending section 130. The end 132 of the Conveyor 120 willopen to a chute 134. The chute 134 can be directed toward the desiredpurposes at the fracturing site. As such, the array of containers 110,112, 114 and 116 can be configured so as to replace existing storagefacilities at the fracturing site. The support structure 118, along,with the conveyor 120, can be easily transportable by a truck upon aroadway because of the use of the wheels 136. The forward end 138 can besuitably connected to a truck so as to allow for the easy transport ofthe system of the present invention.

FIG. 10 illustrates the placement of the containers 110, 112, 114 and116 upon the support structure 118. The end 138 includes a suitablehitch connection for attachment to a truck. The conveyor 120 extendsbelow the containers 110, 112, 114 and 116 so as to deliver the proppantto the chute 134. FIG. 10 illustrates that the chute 134 is suitablypivotable in cooperation with the end 132 of the conveyor 120 so as toallow for the controlled and directed discharge of the proppant to thedesired location.

The container 10 of the present invention is manufactured as a singleunit. The gate 44 of the container 10 is specifically engineered toalign with the actuator 70 located on the conveying system. The actuatoris hydraulically controlled and accepts the pin 48 which is attached tothe gate 44. When the actuator 70 is activated, the gate 44 moveshorizontally so as to allow for the discharge of proppant therefrom.

The container of the present invention can be specifically applied fortransport via rail. In particular, the railcar can be designed so as toaccommodate up to four containers 10. As such, the railcar can carryapproximately 180,000 pounds of proppant when the four containers areplaced on the railcar. The railcar can be similar to current inter-modalrailcars that carry twenty foot, forty foot and fifty-three footinter-modal containers. The railcar would include typical inter-modalload-locks which are evenly spaced down to chassis of the railcar. Thecontainer should be constructed of materials wide enough to keep theoverall loaded weight of the container under currently regulatedrailroad weight guidelines. Additionally, it must be strong enough tobear the load of the loaded container. This development allows sandmines to load proppant directly into a container 10 in order to speed upthe loading process. It also eliminates the need to build a silo storageat the mine site. Once the container arrives at its designated locationor region, trans-load processes to pneumatic trailers, silos or flatstorage, are thus eliminated.

The present invention is an improved delivery system that can be used atthe well-site. The support structure 60 includes a fabricated steelframe upon which multiple containers can be positioned. The containerslock into receptacles that secure the containers to the frame. Thecontainer will then sit above a conveying system that delivers theproppant from the container as the gate is opened to a master-conveyingbelt. The cradle is outfitted with a hydraulic system which can controlthe opening and closing of the gates. The containers of the presentinvention can be combined as an attachment or cartridge compatible withexisting devices known as SAND KINGS™, SAND CHIEFS™ and SAND DRAGONS™.By replacing existing hoppers on these devices with the removablecontainers of the present invention, even greater efficiencies can beattained in the proppant delivery process.

The conveying system of the present invention is an alternative methodof delivering proppant from the container to the blender belt for themixing unit once delivered to the well-site. The conveying system of thepresent invention provides all of the functionality commonly seen in theSAND MASTER™, SAND KING™, SAND DRAGON™, SAND MOVE™, etc. As such, thepresent invention allows the flow of sand to be metered onto theconveyor belt through a hydraulic system of flow gates. The container isfirst lifted into position onto the support structure. The bottom flowgate is received by the receptacle of the hydraulic actuator so as tocreate a lock between the in of the gate and the hydraulic system. Thehydraulic system then opens the flow gate and the proppant so as togravity-feed into a hopper located on the support structure. Another setof flow gates associated with the hopper system are then opened by wayof another hydraulic system. This allows the proppant to be metered andto flow onto a conveyor belt. The conveyor belt can then deliver theproppant to the blender or the T-Belt. The proppant can then be mixedwith other materials in the blender.

Currently, expensive pneumatic bulk trucks are utilized in the deliveryof proppant to a well-site. Once on-site, the trucker employs a powertake-off unit to “blow” the sand into the sand storage devices. Thisdelivery often takes over one (1) hour to complete. By delivering sandto the well in the ten-foot containers of the present invention, the useof expensive pieces of specialized equipment is eliminated. Thecontainer can ride on a standard flatbed, step-deck, low-boy, or othermore commonly-used trailer. As such, the process of the presentinvention is able to tap into a much larger universe of availabletrucking capacity. This can reduce the transportation costs to the well.While pneumatic trailer deliveries are priced in “round trip” miles, thedelivery of the container of the present invention by a more commonpiece of equipment (capable of getting a “back-haul”) significantlyreduces the overall transportation cost. As an example, there is a greatneed for parts, tools and other wellhead equipment to be taken off thewell-site for repair or return to a manufacturer or rental company. Theflatbed trailer, now empty, has the ability to accept that load while itis on-site rather than calling in another trucking company to providethat service. The reduced need for “hot-shot” service is anothersignificant value to the service company and ultimately the explorationand production company.

In terms of returning empty containers to the sand distributionfacilities, a total of four (4) empty containers can be returned by asingle flatbed trailer. This provides a 4:1 level of efficiency inremoving the containers from the well-site. Additionally, at forty footcontainer chassis will be used in the movement of both empty and fullcontainers. The support structure, just like the containers, can bedelivered to the well-site by a typical flatbed truck. The supportstructure could be towed via, truck to the site in manner similar to anyother trailer.

Another advantage to the present invention is the small footprint thatthe ten-foot ISO containers of the present invention occupy relative tothe capacity of sand that they can store. When the containers arestacked three high, the containers can store approximately 135,000pounds in a footprint of eighty square feet. The available space at thewellhead, and in potential proppant minimizes the footprint that isrequired for a given amount of proppant at such a location.

Since environmental and safety concerns surrounding well-site operationsis becoming an increasing concern, the present invention minimizes theamount of particulate matter that is released into the air. Proppant iscurrently delivered to the frac site via pneumatic trailers. Pneumaticpressure is used to pressurize the trailer and then “blow” the materialinto a sand storage unit. This process creates an immense amount ofparticulate matter than can then be inhaled by personnel at thefrac-site. Additionally, while blowing the sand into the sand storagefacility, the sand storage facility must vent the pressurized air to theatmosphere. This creates an even greater exposure to particulate matter.The constant need to take delivery of proppant on-site creates aconstant environment of dust and small particles in the air. Since thepresent invention eliminates pneumatic deliveries, the process of thepresent invention significantly reduces the amount of particulate matteron the frac-site. The gravity-feed delivery method front the containerto the blender greatly improves the safety of well-site personnel.

The present invention also serves to reduce trucking emissions byreducing the amount of trucks that are being used or waiting. The safetyat the wellhead is improved by reducing such truck traffic.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof. Various changes in the details ofthe illustrated construction, or in the steps of the described method,can be made within the scope of the present invention without departingfrom the true spirit of the invention. The present invention should onlybe limited by the following claims and their legal equivalents.

That claimed is:
 1. A method of unloading proppant at a well site, themethod comprising: a) removing a plurality of containers that containproppant from transport road vehicles when positioned adjacent a wellsite; b) transferring the plurality of containers to a support structureat a well site positioned to overlay a common conveyor after removalfrom the transport road vehicles, the support structure configured toinclude a plurality of cradles that correspond to the plurality ofcontainers transferred thereto; c) discharging the proppant within eachof the plurality of containers when positioned on the support structureand within the plurality of cradles from the bottom of each of theplurality of containers onto the conveyor; and d) conveying the proppantaway from the containers toward a desired location at a well site. 2.The method of claim 1, further comprising: after step a), stacking theplurality of containers in a vertical orientation so that a bottom orthe one or more of the plurality of containers overlies a top of anotherone or more of the plurality of containers to reduce the footprint ofthe area required for storage of the proppant at the well site.
 3. Themethod of claim 1, further comprising: directing the proppant from theconveyor to a desired location with a chute attached to the supportstructure and configured to receive the proppant from the conveyor. 4.The method of claim 1, further comprising: controlling the flow ofproppant onto the conveyor with one or more flow gates positionedadjacent the plurality of containers when positioned on the supportstructure and the conveyor, the one or more flow gates configured tomove between closed and open positions.
 5. The method of claim 4,further comprising: controlling the one or more flow gates with one ormore actuators attached to the one or more flow gates and configured tomove the one or more flow gates in discrete increments between theclosed and open positions.
 6. The method of claim 4, wherein step b)includes lifting each of the plurality of containers with a forklift andsetting each of the plurality of containers on top of the supportstructure.
 7. The method of claim 1, wherein step c) includes directingthe flow of proppant from each of the plurality of containers to theconveyor through one or more hoppers, and the method further comprisesdelivering the proppant from the conveyor to a blender.
 8. The method ofclaim 1, further comprising: transporting the support structure from onelocation within the well site to another location within the well siteon wheels attached to the support structure.
 9. The method of claim 1,wherein each of the plurality of containers has an open area adjacent abottom of the respective plurality of containers to allow for visualaccess into a portion of the containers.
 10. A method for storing andunloading of proppant at a well site, comprising: a) removing aplurality of containers that contain proppant from one or more transportroad vehicles when positioned adjacent a well site; b) stacking theplurality of containers in a vertical orientation so that a bottom ofone or more of the plurality of containers overlies a top of another oneor more of the plurality of containers so as to define a container stackand thereby reduce the footprint of the area required for storage of theproppant at the well site; c) transferring the plurality of containersfrom the container stack to a support structure configured to include aplurality of cradles to receive the containers, each of the plurality ofcradles configured to position an outlet of one of the plurality ofcontainers adjacent a conveyor; d) selectively opening one or more ofthe outlets of the plurality of containers to discharge proppant fromthe bottoms of the plurality of containers onto the conveyor; e)conveying the proppant away from the containers toward a desiredlocation at a well site.
 11. The method of claim 10, further comprising:directing the proppant from the conveyor to a desired location with achute attached to the support structure and configured to receiveproppant from the conveyor.
 12. The method of claim 10, furthercomprising: controlling the flow of proppant from each of the pluralityof containers onto the conveyor with a flow gate positioned adjacent thecontainer and the conveyor, the flow gate configured to move betweenclosed and open positions.
 13. The method of claim 12, furthercomprising: controlling the flow gate with one or more actuatorsattached to the flow gate and configured to move the flow gate indiscrete increments between the closed and open positions.
 14. Themethod of claim 10, wherein steps a) and c) include lifting each of theplurality of containers with a forklift to respectively stack andtransfer the plurality of containers.
 15. The method of claim 10,further comprising: transporting the support structure from one locationto another on wheels attached to the support structure.
 16. The methodof claim 10, wherein the plurality of containers have open areasadjacent the bottoms of the containers to allow for visual access insidea portion of the containers.
 17. The method of claim 10, furthercomprising: delivering the proppant from the conveyor to a blender. 18.A method for controlling the unloading of proppant, the methodcomprising: a) setting a plurality of containers that each containproppant onto a support structure configured to include a plurality ofdiscrete cradles each positioned to overlay a common conveyor at a wellsite, each of the plurality of cradles configured to receive one of theplurality of containers and positioned to be separated from the conveyorby one of a plurality of hoppers, an outlet of each the plurality ofcontainers positioned to overly the one of the plurality of hoppers of acorresponding cradle of the plurality of discrete cradles; b)discharging the proppant from the bottoms of the plurality of containersinto the plurality of hoppers; c) selectively moving one or more flowgates from a closed to an open position to allow proppant to pass fromthe plurality of hoppers to the conveyor at a desired flow rate; d)conveying the proppant away from the plurality of containers toward adesired location at a well site.
 19. The method of claim 18, furthercomprising: directing the proppant from the conveyor to a desiredlocation with a chute attached to the support structure and configuredto receive proppant from the conveyor.
 20. The method of claim 18,further comprising: controlling the one or more flow gates with one ormore actuators attached to one or more of the one or more flow gates andconfigured to move the one or more flow gates in discrete incrementsbetween the closed and open positions.
 21. The method of claim 20,wherein step b) includes using a forklift to set each of the pluralityof containers on one of the plurality of cradles of the supportstructure.
 22. The method of claim 18, further comprising: transportingthe support structure from one location at the well site to anotherlocation at the well site on wheels attached to the support structure.23. The method of claim 18, further comprising: prior to step a),stacking the plurality of containers vertically with one bottom of acontainer overlying a top of a container to reduce the footprint of thearea required for storage of the proppant at the well site.
 24. Themethod of claim 18, further comprising: subsequent to steps b) and c),removing one or more empty containers from the support structure andreplacing them with one or more containers that contain proppant. 25.The method of claim 18, wherein the containers have open areas adjacentthe bottoms of the containers to allow for visual access inside aportion of the containers.
 26. The method of claim 18, furthercomprising: delivering the proppant to a blender.
 27. A method ofdelivering proppant material at a well site, the method comprising: a)removing a container that contains proppant at a well site from atransport road vehicle; b) stacking the container that contains proppantin a storage area at the well site to reduce the footprint of the arearequired for storage of the proppant at the well site; and c)positioning one or more empty containers onto the transport road vehiclefor transport away from the well site, the one or more empty containerscomprises less than five empty containers.